Heat exchanger with accessible core

ABSTRACT

A heat exchanger may include a core control assembly movable between compressed and uncompressed positions, and a core. The core may have a plurality of layers with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery of the layers. The core control assembly may be operably coupled to the core to compress the core when the core control assembly is in its compressed position and to permit the core to expand from its compressed state when the core control assembly is moved away from its compressed position. The expansion of the core increases a cross-sectional area of the passages at the periphery of the core.

REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/176,893 filed on May 9, 2009.

TECHNICAL FIELD

The present disclosure relates generally to heat exchangers.

BACKGROUND

Conventional heat exchangers are configured to transfer heat from a treatment fluid flowing on one side of a barrier to a working fluid flowing on another side of the barrier. For example, stacked plate heat exchangers include a shell for housing a plurality of corrugated heat transfer plates. The plates are arranged face-to-face in a stack along a longitudinal direction. Collectively, the adjacent plates in the stack define transversely extending passages for the treatment fluid that are interdigitated with transversely extending passages for the working fluid.

SUMMARY

A heat exchanger may include a core control assembly movable between compressed and uncompressed positions, and a core. The core may have a plurality of layers with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery of the layers. The core control assembly may be operably coupled to the core to compress the core when the core control assembly is in its compressed position and to permit the core to expand from its compressed state when the core control assembly is moved away from its compressed position. The expansion of the core increases a cross-sectional area of the passages at the periphery of the core.

In another form, a heat exchanger may include a core, a core control assembly and a housing. The core may have a longitudinal axis and an periphery disposed about the longitudinal axis, and a plurality of resilient corrugated layers stacked along the longitudinal axis with a plurality of passages interleaved therebetween, with a portion of the passages extending and open to the periphery. The core control assembly may have a pair of end plates disposed on opposed ends of the core and at least one intermediate member interconnecting the end plates to control movement of the core control assembly between a compressed position where the end plates are spaced apart by a first distance and an uncompressed position where the end plates are spaced apart by a second distance greater than the first distance. The core expands to increase a cross-sectional area of the passages at the periphery when the core control assembly is moved to the uncompressed position. The housing may have a shell and at least one cover mounted to the shell to surround the core and the core control assembly.

An exemplary method of accessing a heat exchanger core may include moving an intermediate member in a first direction, and moving a core control assembly that is associated with the intermediate member toward an uncompressed position with respect to a base. The method may further provide for expanding the core along a longitudinal axis between the ram and the base, with the core having an periphery and a plurality of resilient corrugated layers stacked along the longitudinal axis with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery and having a cross-sectional area at the periphery, and increasing the cross-sectional area of the passages at the periphery.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of preferred embodiments and best mode will be set forth with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of an exemplary stacked plate heat exchanger having one embodiment of a housing;

FIG. 2 is a cross-sectional axial view of the heat exchanger of FIG. 1;

FIG. 3 is a partially exploded view of a portion the core of FIG. 2, showing an exemplary spacer arrangement;

FIG. 4 is an enlarged fragmentary cross-sectional view of the core as taken along line 4-4 of FIG. 3, showing two exemplary cassettes forming a portion of the core;

FIG. 5 is an enlarged cross-sectional view of a portion of the core in a compressed state;

FIG. 6 is a perspective view of the core control assembly and core of FIG. 2;

FIG. 7 is an enlarged and partially sectioned side view of a portion of the core control assembly of FIG. 6;

FIG. 8 is a perspective view of the core control assembly of FIG. 6, showing an exemplary drive mechanism moving the core control assembly from an uncompressed position to a compressed position to compress the core;

FIG. 9 is a perspective view of the core control assembly of FIG. 8, showing the drive mechanism moving the core control assembly from the compressed position to the uncompressed position to expand the core;

FIG. 10 is a perspective view of the core control assembly of FIG. 6, showing the core control assembly in its uncompressed position with an exemplary spacer removed from a portion of the core to facilitate access to that portion;

FIG. 11 is an exploded perspective view of another exemplary core control assembly, showing the core control assembly dismantled and the core removed;

FIG. 12 is a perspective view of another exemplary core control assembly with a drive system in another form;

FIG. 13 is an enlarged and partially sectioned side view of a portion the core control assembly as taken along line 13-13 of FIG. 12;

FIG. 14 is an enlarged end view of a portion of the core control assembly as taken along line 14-14 of FIG. 12;

FIG. 15 is an enlarged and partially sectioned side view of a portion of still another exemplary core control assembly;

FIG. 16 is a perspective view of another exemplary core control assembly;

FIG. 17 is an enlarged and partially sectioned side view of a portion of the core control assembly of FIG. 16;

FIG. 18 is an enlarged and partially sectioned side view of a portion of a another exemplary core control assembly having a biasing member in one form;

FIG. 19 is an enlarged and partially sectioned side view of a portion of another exemplary core control assembly having a biasing member in another form;

FIG. 20 is a perspective and sectioned view of another exemplary core control assembly;

FIG. 21 is a perspective view of another exemplary core control assembly;

FIG. 22 is an enlarged side view of a portion of the core control assembly of FIG. 21;

FIG. 23 is a fragmentary side view of another core control assembly that facilitates expansion of the core; and

FIG. 24 is a fragmentary view of a spreader that may be used to further separate, or hold separated, adjacent cassettes.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring in more detail to the drawings, FIG. 1 illustrates an exemplary heat exchanger 10 for transferring heat between different fluids. The heat exchanger 10 may be substantially similar in general operation and construction to that disclosed in U.S. Pat. No. 7,004,237, the disclosure of which is incorporated herein by reference in its entirety. Although the heat exchanger 10 is illustrated as being generally cylindrical, it can be of any suitable shape and size.

In general, as shown in FIGS. 1-3, the heat exchanger 10 may include a housing 11 defining an interior volume 12, and a core 13 disposed within the interior volume 12. The housing 11 may have a shell 20 and one or more covers or other mating parts to define the interior volume 12. The housing 11 in this implementation may have a first cover 21, a second cover 22 and the shell 20 with opposed ends carrying the first and second covers 21, 22 to define the interior volume 12 therebetween. The covers 21, 22 may be plate-like components, and the shell 20 may be an open-ended hollow component preferably of cylindrical shape as shown. The core 13 may have a longitudinal axis 14, a periphery 15 and a plurality of fluid paths or passages 16, 17 (FIG. 4). At least a portion of the passages 17 may extend and be open to the periphery 15.

As best shown in FIG. 1, the housing 11 may carry or be communicated with fittings that may be adapted to convey treatment and working fluids into and out of the heat exchanger 10, and any suitable quantity and arrangement of fittings may be used. For example, the first cover 21 in one form may carry a first inlet fitting 24 extending therethrough. The first inlet fitting 24 may be communicated with the core and may be adapted to be coupled to, for example, a supply conduit from a treatment fluid source (not shown) having a fluid that requires heating or cooling treatment. In addition, the first cover 21 may carry or be communicated with a first outlet fitting 28 that may be communicated with the core 13 and may be adapted to be coupled to a return conduit leading to the treatment fluid source. Further, the shell 20 may carry or be communicated with a second inlet or fitting 32 that may be adapted to communicate, for example, a working portion of a heat exchanging system such as a cooler or a heater (not shown), with the interior volume 12 of the housing 11. Also, the shell 20 may carry or be communicated with a second outlet fitting 36 that communicate the interior volume 12 of the housing 11 with the working portion of the heat exchanging system. Of course, the fittings may be carried by any portion of the housing 11 in any suitable manner, including welding, press-fit, threading, or the like. Those skilled in the art will recognize that the fittings and fluids could be reversed such that the second inlet and second outlet permit flow of the treatment fluid, and the first inlet and first outlet permit flow of the working fluid, and more fittings, inlets and/or outlets may be provided.

Referring to FIG. 2, the heat exchanger may have a pair of seals 39, 40 that may be disposed between the housing 11 and the core 13 and may extend axially along the periphery of the core 13, such that the seals 39, 40 may direct the working fluid from the second inlet fitting 32 through the core 13 and out the second outlet fitting 36. These seals may be substantially similar to those disclosed in U.S. Pat. No. 7,004,237. Of course, the heat exchanger 10 may have any suitable seal or obstruction or omit the same according to design requirements.

The core 13 can be any suitable heat exchanger core but, as shown, is preferably a stacked plate type of heat exchanger. As shown in FIGS. 6 and 7, the heat exchanger 10 may further include a core control assembly 18 which may have at least one movable plate or ram 19 that may be movable along the longitudinal axis 14 of the core 13 to clamp and/or compress the core. Accordingly, when the force exerted on the core by the ram 19 is reduced or removed, the core 13 may expand or be expanded to increase a cross-sectional area of the passages 17 at the periphery 15 of the core 13. This may facilitate access to the passages 17 at the periphery 15 adjacent to the housing 11 to, for example, remove foulants on or between surfaces of the core within the passages.

Referring to FIG. 3-5, the core 13 may have a plurality of corrugated layers 41 stacked along the longitudinal axis 14 with the fluid passages 16, 17 interleaved therebetween. In particular, the layers 41 in one implementation may generally include a stack of cassettes 42. As best shown in FIG. 4, each cassette 42 may have an upper plate 44 and a lower plate 45 welded to the upper plate 44 along the periphery 15. Further, each upper and lower plate 45 may be corrugated, somewhat flexible and resilient, and may be disposed on opposite sides of, or may instead extend across or away from a plane 43 that may be transverse to the longitudinal axis 14. The plates 44, 45 may include two or more protuberances 46 that may be disposed about a pair of ports 47. The protuberances 46 on each cassette 42 and the portions between adjacent protuberances may be welded to corresponding portions on an adjacent cassette. The cassettes 42 may be communicated with each other through the ports 47 to define an inlet passage 48 (FIGS. 4-6) that may extend longitudinally from the first inlet fitting 24 through each of the cassettes 42. The cassettes 42 may also define the treatment fluid passages 16 that may each extend transversely from the inlet core passage 48, and an outlet passage 49 (FIG. 6) that may extend from each of the passages 16 to the first outlet fitting 28. Accordingly, the core 13 may convey treatment fluid from the first inlet fitting 24, through the inlet passage 48, the treatment fluid passages 16 and the outlet passage 49 and out through the first outlet fitting 28.

As also shown FIGS. 4 and 5, the stack of cassettes 42 may define the working fluid passages 17 interleaved therebetween, which are not communicated with the treatment fluid passages 16. The working fluid passages 17 may extend and may be open to the periphery 15 of the core 13 adjacent to the shell 20. Accordingly, the heat exchanger 10 may convey working fluid from the second inlet fitting 32 through the working fluid passages 17 and out the second outlet fitting 36. Of course, the working and treatment fluid passages may instead be configured to carry the other of the two fluids.

Referring to FIGS. 3 and 5, the core 13 may also have one or more spacers 50 that may be disposed within the working fluid passages 17 to provide a path for heat transfer by conduction between adjacent cassettes and increase heat transfer between the fluids conveyed through the stack. The spacers 50 in one form may be a plurality of metal mesh plates 51, each overlying a portion of the surface area of a cassette with at least two of the plates 51 having cutouts 52 or otherwise being shaped to fit around the ports 47 to facilitate removal from and insertion of the mesh plates between cassettes 42 and into the core 13. This may increase the working distance between cassettes when the spacers 50 are removed to, for example, facilitate cleaning and/or servicing the core 13. Each plate 51 may have a plurality of holes, baffles or other guide members to disturb the flow of the working fluid that may be conveyed through the passage 17. Of course, the spacers 50 may be planar, corrugated and/or aspirated or have various other suitable shapes.

Referring now to FIG. 6, the ram 19, in one form may be an end plate carried by one end of the core 13 in any suitable manner including welding, bonding, adhesion, mechanical fasteners or the like. The ram 19 may be of any suitable shape and may have an inlet hole 53 that may define part of the inlet passage 48 and may carry or may be communicated with the first inlet fitting 24 and an outlet hole 54 that may define part of the outlet passage 49 and may carry or may be communicated with the first outlet fitting 28. In addition, the ram 19 may have a first surface 55 with one or more seats or pockets 56 which may each include an anti-rotation feature, such as a hexagonal or other noncircular shape. Of course, the ram may have any number of pockets with or without anti-rotation features. As best shown in FIG. 7, each pocket 56 may have one or more sidewalls 58, a bottom surface 59 that may extend between the sidewalls 58, and a hole 61 that may extend through a second surface 60 of the ram and open to the pocket 56.

As also shown in FIG. 7, the core control assembly 18 may have a base 69 at an end of the core 13 opposite the ram 19. The base in one implementation may be an end plate which may be carried by the core 13 in any suitable manner including welding, bonding, adhesion, fasteners or the like, or it may be separate from the core. Also, the base 69 may have a first surface 70 with one or more seats or pockets 71 which may each include an anti-rotation feature (not shown), such as a hexagonal or other noncircular shape. Of course, the base may have any number of pockets with or without anti-rotation features. Each pocket 71 may have one or more sidewalls 73 and an end surface 74 that may extend between the sidewalls 73. The base 69 may also have a second surface 75 with a plurality of holes 76 that each may extend and may be open to a respective pocket 71.

Referring still to FIG. 7, the core control assembly 18 may also have one or more intermediate members that control, assist or limit relative movement between the ram 19 and base 69. The intermediate members may include or be formed of multiple components. In one implementation, the intermediate members include first connectors 62 that may be carried by or adjacent to the ram 19 or other suitable portion of the exchanger. The first connector 62 in this form may be a bolt that may have a hexagonal, circular or noncircular head 64 (FIG. 6) that may be received within the pocket 56, a shank which may be inserted through the hole 61 and may have non-threaded portion 65, a threaded portion 67, and a shoulder 66 or other stop surface between them. The threaded shank portion 67 may have right hand threads thereon. Of course, the first connector 62 may instead be an integral portion of a unitary or single-piece ram, may instead have any number of connectors that may have left hand threads with or without a shoulder or head, may be rotatably carried by the ram and/or have various other suitable fastening features.

The intermediate members may also include one or more second connectors 77 that may be carried by the base 69 or other suitable portion of the exchanger. The second connector 77 may have a head 79 that may be received within the pocket 71 and may engage the anti-rotation feature or other portion of the base 69 to limit or prevent rotation of the connector 77. The connector 77 may also have a shank received through the hole 76, and the shank may have a non-threaded portion 80, a threaded portion 82, and a shoulder 81 or other stop surface. The threaded portion 82 may have left hand threads thereon. Of course, the second connector 77 may instead be an integral portion of a unitary or single-piece base, and/or have any number of pockets and connectors, may have right hand threads with or without a shoulder or head, may be rotatably carried by the base and/or may have various other suitable fastening features.

The core control assembly intermediate members may also include a series of third connectors 84 that may each interconnect one pair of the first and second connectors 62, 77. As best shown in FIG. 8, in one implementation, each third connector 84 may be a tube or sleeve 85 having opposed blind bores 87, 89. The bore 87 may include threads adapted to mate with the threaded shank portion 67 of the first connector. The bore 89 may include threads adapted to mate with the threaded shank portion 82 of the second connector 77. Further, each third connector 84 may have an attachment feature 91, which in this implementation is a notch or hole 91 formed in the sleeve 85.

Referring to FIGS. 8 and 9, the core control assembly 18 may also have a drive system 93 that may be carried by a respective one of the attachment features 91 of the third connectors 84. For example, the drive system 93 in one form may simply be one or more tools 94 having an end received within the holes 91 or carried by other attachment features, to manually rotate or otherwise move each third connector 84 in a desired direction to move the ram 19 between its uncompressed position (FIG. 8) and its compressed position (FIG. 9). Of course, the drive system may instead have any number of tools carried by other portions of the assembly or be replaced with any suitable drive mechanism. Further, the base may move relative to the ram, and both the base and ram may be moved relative to each other between compressed and uncompressed (or less compressed) positions.

To install the core 13 and core control assembly 18 within the housing 11, a technician may use the tool 94 to rotate the third connector 84 in a first direction and move the ram 19 from its uncompressed position toward its compressed position. For example, as shown in FIG. 8, the technician may use the tool 94 to incrementally rotate each individual third connector 84 in the first direction to draw the ram 19 closer to the base 69 and compress the core 13 therebetween. This may be done until the third connector 84 abuts one or both of the shoulders 66, 81 to ensure desired compression, but prevent over compression or damage to the core. The core 13 in its compressed state sandwiches the spacers 50 between adjacent cassettes 42 and may provide a path of heat transfer by conduction to increase heat transfer through the stack (FIG. 5) and between the fluids conveyed therein. The core 13 and core control assembly 18 may then be placed within the shell 20 and the covers 21, 22 may be attached to the shell 20.

To access the core 13 to, for example, service the core 13, the technician may remove the first cover 21 and/or shell 20 from the housing 11 to expose the core 13 and core control assembly 18. The technician may then use the tool 94 to move the ram 19 from its compressed position (FIG. 9) toward its uncompressed position (FIG. 8). For example, as shown in FIG. 9, the technician may use the tool 94 to rotate each third connector 84 in the second direction to displace the ram 19 away from the base 69 and expand the core 13 connected therebetween. The protuberances 46 may be resilient and may facilitate in expanding the core 13 along its longitudinal axis 14 toward its uncompressed (or less compressed) state. As shown in FIG. 10, expansion of the core 13 may increase the cross-sectional area of the working fluid passages 17 at the periphery 15 of the core 13, to facilitate removal of the spacers 50 from the core 13 and allow a technician to insert a tool, such as a flat metal bar 95, at the periphery 15 of the core 13 into the portions that had previously carried the spacers 50. Accordingly, the technician may then use the bar 95 to remove any debris or foulants on or at surfaces of those portions. Also, the housing 11 may be reassembled with the core 13 in its expanded state, so that a cleaning solvent may be conveyed through the passages 16, 17 at a high pressure or pressurized fluid may be applied to the core when the core is outside of the housing. Once servicing has been completed, the spacers 50 may be reinserted within the core 13, and the technician may rotate the third connectors 84 in the first direction to return the ram 19 to its the compressed position.

FIG. 11 illustrates another embodiment of an exemplary heat exchanger 110 that may transfer heat between different fluids. This embodiment is similar in many respects to the embodiment of FIG. 6, and corresponding elements in FIG. 11 are designated by the numerals of FIG. 6 with the addition of the prefix “1” for each numeral. Further, the descriptions of the embodiments are incorporated by reference into one another and the common subject matter may generally not be repeated here. As compared to the embodiments of FIG. 6, the ram 119 and the base 169 may be not be welded or otherwise attached to the core 113 such that the ram 119 and the base 169 may be completely detached from each other to facilitate removal of the core 113 from the core control assembly 118 to, for example, permit servicing or replacing the core 113.

Referring to FIGS. 12-14, another exemplary heat exchanger 210 is illustrated without its housing. The heat exchanger 210 may have a core control assembly 218 and may be similar to the heat exchanger 10 of FIGS. 6-8 having the core control assembly 18. Corresponding elements in FIGS. 12-14 are designated by the numerals of FIGS. 6-8 with the addition of the prefix “2” for each numeral. This core control assembly 218, however, has a series of first connectors 262 each rotatably carried by one of the ram 219 and the base 269 and having a threaded end portion 267. Further, the other of the ram 219 and the base 269 may have a plurality of second connectors 277 having threaded portions 282 that may each engage the threaded end portion 267 of a respective one of the first connectors 262. This core control assembly 218 may also have another exemplary drive system 293 that may operably interconnect the first connectors 262 to simultaneously drive the first connectors 262, as compared to the tool(s) 94 of FIG. 8 that are individually and incrementally operated to individually rotate the third connectors 84 and operate the core control assembly 18.

The ram 219 in this form may have a first surface 255 with a series of spaced apart pockets 256. As best shown in FIG. 13, each pocket 256 may have one or more sidewalls 258 and a bottom surface 259 extending between the sidewalls 258 with an attachment feature, such as a circular seat 256 a, therein. The ram 219 may also have a second surface 275 with a plurality of holes 276 that may each extend and may be open to a respective one of the pockets 256 during assembly. Referring back to FIG. 12, the ram 219 may also have a series of channels 295 extending between and interconnecting adjacent pockets 256.

As also shown in FIG. 13, each first connector 262 may be rotatably carried by the ram 219 with a head 264 received in one of the pockets 256. At least one of the first connectors 262 may include a head 264 with an end 264 a having a drive feature such as a hexagonal or non-circular shape, connector or other feature that may be configured to be driven by a tool, such as a torque wrench or other suitable tool to facilitate rotating the connector 262. In addition, the first connectors 262 may each have a shank 265 extending from the head 264 and through the hole 276 in the ram 219. The shank 265 may include the threaded end portion 267 which may be defined by a blind bore 265 a tapped with right hand threads 268. Of course, the assembly 218 may have any number of first connectors 262 which may be rotatably carried by the ram 219 or may instead be externally threaded bolts or other suitable third connectors.

The second connectors 277 in this form may be bolts or threaded rods carried by the base 269 in any suitable manner, including welding, adhesion, fasteners, or the like. The second connector 277 may have right hand threads 282 that may engage the threads 268 of the end portion 267. It is contemplated that the second connectors 277 may instead be sockets or other suitable connectors carried by the base and configured to engage the first connectors 262.

The drive system 293 in this implementation may be a belt or chain driven system with one third connector being a driving member and the remaining third connectors being driven members. In particular, the chain drive system 293 may include a series of sprockets 298 that may each be carried by a respective one of the heads 264 of the first connectors 262, for co-rotation with the associated first connector 262. The system 293 may also have a chain 299 operatively associated with the sprockets 298 and routed within the channels 295. All sprockets may be identical for uniform rotation. Accordingly, a technician may use a torque wrench or other tool engaged with the head end 264 a to operate the drive mechanism to simultaneously rotate all first connectors 262 at the same rate to uniformly and evenly move the entire core control assembly 218 between the compressed and uncompressed positions, without separately and incrementally adjusting individual connectors 262. Compression of the core 213 may be limited by engagement of the stop surfaces 266, 281 of the connectors 262, 277.

Referring to FIG. 15, another exemplary core control assembly 318 may have a third connector 384 and first and second connectors 362, 377 and may be similar to the core control assembly 18 of FIG. 8 having the third connector 84 and first and second connectors 62, 77. Corresponding elements in FIG. 16 are designated by the numerals of FIG. 7 with the addition of the prefix “3” for each numeral. The first connector 362 in this implementation may be a hole 301 formed in the ram 319 with the hole 301 having right hand threads 368. Similarly, the second connector 377 in this implementation may be a hole 302 formed in the base 369, with the hole 302 having left hand threads 383. Finally, the third connector 384 in this form may be a rod 385 that may have one end 387 with right hand threads 388 to engage the right hand threads 368 of the hole 301, and another end 389 with left hand threads 390 to engage the left hand threads 383 of the hole 302. Each third connector 384 may also have an attachment feature, which in this form may be a hole 391 that may receive a tool 394 or other drive mechanism. Accordingly, a technician may use the tool 394 to incrementally rotate each third connector 384 in one direction to move the ram 319 and/or base 369 toward the uncompressed position and in another direction to move the ram 319 toward its compressed position.

FIGS. 16 and 17 illustrate yet another embodiment of an exemplary heat exchanger 410 without its housing to show a core control assembly 418 in another form that may be movable between compressed and uncompressed positions. This embodiment is similar in many respects to the embodiment of FIGS. 6 and 7, and corresponding elements in FIGS. 16 and 17 are designated by the numerals of FIGS. 6 and 7 with the addition of the prefix “4” for each numeral. The descriptions of the embodiments are incorporated by reference into one another and the common subject matter may generally not be repeated here.

As compared to the embodiments of FIGS. 6 and 7, each third connector 484 in this form may have a plurality of leg portions or segments in serial connection between the first and second connectors 462, 477 respectively carried by the ram 419 and base 469. One or more of the segments may be moved to increase or decrease the overall length of the entire third connector. As best shown in FIG. 17, each third connector 484 may include a first segment, such as a tube 485 a, that may have one end 487 a that may be threaded in a first direction to engage the threaded end portion 468 of the first connector 462 and another end 489 a that may be threaded in a second direction opposite the first direction. Also, each third connector 484 may include a second segment, such as a rod 403, which may have one end 404 that may be threaded in the second direction to engage and be received within the end 489 of the first tube 485 a opposite the first connector 462. The rod 403 may have another end 405 that may be threaded in the first direction. Further, each third connector 484 may include a third segment, such as another tube 485 b, that may have one end 487 b that may be threaded in the first direction to engage and receive the end 405 of the rod 403 opposite the other tube 485 a. The tube 485 b may have another end 489 b that may be threaded in the second direction to engage and receive the threaded end portion 483 of the second connector 477. Of course, each segment may have shoulders, abutments or other features to limit the extent by which one segment can be inserted into another segment and define the distance along which the core control assembly may move between the compressed and uncompressed positions. It is contemplated that each leg may have various other suitable segments as required by design.

Referring to FIG. 18, a core control assembly 518 in another implementation may be similar to the core control assembly 18 of FIG. 7 and corresponding elements in FIG. 18 are designated by the numerals of FIG. 7 with the addition of the prefix “5” for each numeral. However, the core control assembly 518 may include intermediate members that facilitate expanding the core by increasing the distance between the ram 519 and base 569. Compression of the core may be achieved by another device. For example, installation of a cover onto the housing of the heat exchanger may compress the core within the housing. Then, removal of the core from the housing may permit the core to expand or be expanded. As shown in FIG. 18, the intermediate members may include a first connector 562 carried by the ram 519, a second connector 577 carried by the base 569, one or more than one biasing member 506 acting on one or both of the rods 562, 577 tending to separate them, and a third connector 584 disposed around the ends of the rods 562, 577 and the biasing member 506. Of course, the biasing member 506 may instead be configured to move the ram 519 toward the compressed position. At least some of the first and second connectors 562, 577 in this form may not have threads, but rather may be slidably carried within opposed ends of the third connector 584. The biasing member 506 may be a spring, or the biasing member 506 may instead be a hydraulic-actuated cylinder, a pneumatic cylinder (FIG. 19) or any suitable resilient member.

Referring to FIG. 20, another exemplary core control assembly 618 may have a ram 619, a first cover 621 and a pair of second connectors 677 a, 677 b and may be similar to the core control assembly 18 of FIG. 7 having the ram 19, the first cover 21 and the third connector 84. Corresponding elements in FIG. 20 are designated by the numerals of FIG. 7 with the addition of the prefix “6” for each numeral. The core control assembly 618 in this form, however, may have second connectors 677 a, 677 b that may extend through the first inlet and first outlet passages 648, 649 of the core 613, as compared to the connectors 62, 77 of FIG. 7 which extend longitudinally along the periphery 15 of the core 13.

The ram 619 or base 669 in this form may include a first connector 662 which may be in the form of a collar, annular flange or other support with a threaded portion 667 that may be mounted to a respective one of the first inlet and first outlet fittings 624, 628. Of course, the support 662 may instead be carried by the first cover 621 or other portion of the exchanger 610 as desired. Further, each second connector 677 a, 677 b may include a threaded rod 608 that may be threadably carried by a respective one of the support structures 662 and extend through one of the first inlet and first outlet passages 648, 649 toward the base 669. Each second connector 677 a, 677 b may carry a knob, handle 694 or other drive mechanism or system. The second connectors 677 a, 677 b may be incrementally inserted into the core 613 by, for example, using the handles 694 to rotate a respective one of the rods 608 to force the bottom of each rod 608 against the base 669 and raise the ram 619 to spread or expand the core 613 carried thereon to its uncompressed position. The core 613 may be compressed by rotating the second connectors 677 a, 677 b in the opposite direction, or by use of a different mechanism. The first connectors 662 and the second connectors 677 a, 677 b can be removed from the core assembly to permit use of the core assembly.

Referring to FIGS. 21 and 22, another exemplary heat exchanger 710 may have a core 713 may be suspended vertically from its top and a core control assembly 718 in another form that may limit the expansion of the core 713 to, for example, prevent damage to the core that may be caused by its overexpansion. The core control assembly 718 may include a ram 719 and a third connector 784 that may hold the ram 719 in a fixed position between compressed and uncompressed positions. The heat exchanger 710 may be similar to the heat exchanger 10 of FIGS. 1 and 6 having the core 13 and the core control assembly 18. Corresponding elements in FIGS. 21 and 22 are designated by the numerals of FIGS. 1 and 6 with the addition of the prefix “7” for each numeral. The first and second connectors 762, 777 in this form may be first and second straps that may extend from a respective one of the ram 719 and the base 769.

As best shown in FIG. 22, the third connector 784 may be an extension that may have one end slidably carried by the first strap 762 and another end slidably carried by the second strap 777, so that the third connector may limit movement of the first and second straps with respect to one another. For example, the third connector 784 may define a slot or groove 785 with opposed ends 787, 789, and the first and second straps 762, 777 may each carry a projection 700 that may be slidably carried by the third connector 784 within the groove 785 between its opposed ends 787, 789. One skilled in the art will recognize that the third connector may also include one or more catches to hold one or both projections in a fixed position within the groove to adjust the length of the core. Of course, other third connectors may be used to slidably connect the ram 719 to the base 769 and limit movement of one with respect to the other for controlling the expansion and/or elongation of the core. In implementations where the core is vertically suspended such that the weight of the core pulls the core downward thereby expanding the core, the assembly 718 may limit, reduce or prevent over-expansion of the core 713 and reduce or prevent damage thereto.

Another core control assembly 818, as shown in FIG. 23, may include a first connector 862, a second connector 877, and a spring 806 carried by one or both of the first and second connectors. The first connector 862 may be tubular, connected at one end to the ram 819, and have an open end facing the base 869. The second connector 877 may be a rod or shank connected to the base 869 and extending into the open end of the first connector. The spring 806 may be a coil spring carried about the second connector and received at least partially within the first connector. The spring 806 may bear at one end on a shoulder 881 of the second connector 877, and, in assembly, may bear on the ram 819 or a surface within the first connector 862. The first connector 862 may include a slot 892, and an end coil 894 of the spring 806, or a pin or other feature the spring 806 engages, may extend partially out of the slot 892, or through aligned slots 892 if more than one slot 892 is provided. When the core is in its compressed state, the spring 806 is compressed and provides a force tending to separate the ram 819 and base 869. When the force compressing the core is removed or less than that of the spring 806, the spring 806 will tend to increase the distance between the ram 819 and base 869, and or facilitate movement of the ram and/or base to increase the distance between them. A strap 890, tether or other device may limit expansion of the core from its compressed position.

FIG. 24 shows a tool, such as a spreader or wedge 900 that may be used to separate adjacent plates or cassettes of a heat exchanger, or to hold apart adjacent plates or cassettes. The wedge 900 may include a plurality of relatively thin projections 902 that may have inclined surfaces 904 providing an increased cross-sectional area of the projections 902 away from the free end of the projections 902. That is, the projections 902 are smallest at their free end, and get wider away from their free end. In use, the projections 902 may be aligned with gaps between adjacent plates or cassettes, and the wedge may be advanced relative to the core. As the wedge is advanced relative to the core, the projections 902 are inserted further between adjacent plates or cassettes so that increasingly wider portions of the projections 902 engage the plates or cassettes to separate the adjacent plates or cassettes. In this manner, movement of the wedge 900 may spread apart the adjacent plates or cassettes to increase or facilitate expansion of the core, and access to the spaces between adjacent plates or cassettes for cleaning, other maintenance or inspection. The wedge 900 may also be useful to hold apart adjacent plates or cassettes of an expanded core.

Accordingly, as set forth herein, the core control assemblies may include a drive member or other device that clamps and/or compresses the core. The core control assemblies may also or instead enable, facilitate and or limit expansion of the core. In some forms, the core may be compressed by a device other than the core control assembly. For example, in some forms, the core may be compressed by installation of the core within the heat exchanger housing 11, such as when a cover of the housing is installed to enclose the core within the housing.

While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. For example, while the term “connectors” was used to describe various components of the intermediate members that facilitate compression and/or expansion of the core, the connectors may not directly connect the ram and base, and may not be connected together (e.g. a rod may be slidably received within a tube, but not directly connected to the tube, nonetheless, they may be considered connectors in the context of this disclosure). The term “connector” is intended to have a broad meaning relating to components that interconnect or are associated with adjacent structures or features. It is understood that the terms used herein are merely descriptive, rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention. 

1. A heat exchanger, comprising: a core control assembly movable between compressed and uncompressed positions, and a core having a plurality of layers with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery of the layers, wherein the core control assembly is operably coupled to the core to compress the core when the core control assembly is in its compressed position and to permit the core to expand from its compressed state when the core control assembly is moved away from its compressed position, and expansion of the core increases a cross-sectional area of the passages at the periphery of the core.
 2. The heat exchanger of claim 1, further comprising a housing having a shell and at least one cover mounted to the shell, and wherein the core and the core control assembly are disposed within the housing.
 3. The heat exchanger of claim 1, further comprising a drive releasably carried by the core control assembly to move the ram between the compressed and uncompressed positions.
 4. The heat exchanger of claim 1 wherein the core control assembly includes at least one ram movable relative to the core to compress the core and permit the core to be expanded from its compressed state.
 5. The heat exchanger of claim 4 which also includes a base positioned adjacent to the core opposite the ram, and wherein the core control assembly includes one or more intermediate members that interconnect the ram and the base to control movement between the ram and the base.
 6. The heat exchanger of claim 5 wherein the intermediate members include one or more first connectors carried by the ram, one or more second connectors carried by the base and one or more third connectors, with each third connector interconnecting one first connector with one second connectors.
 7. The heat exchanger of claim 4 wherein the core control assembly includes a drive system coupled to the ram to move the ram in one direction to compress the core and in another direction to reduce the compression force on the core.
 8. The heat exchanger of claim 4 which also includes a base positioned adjacent to the core opposite the ram, and the core control assembly includes one or more intermediate members that interconnect the ram and the base to control movement between the ram and the base, and wherein the intermediate members include one or more first connectors carried by the ram, one or more second connectors carried by the base and one or more third connectors, with each third connector interconnecting one first connector with one second connectors, and further comprising a drive system coupled to at least one third connector to move the third connector and thereby move the ram toward or away from the base.
 9. The heat exchanger of claim 8 wherein, when the ram is driven by the drive system, the base may likewise be driven relative to the ram.
 10. The heat exchanger of claim 5 wherein one or both of the ram and the base are fixed to the core.
 11. The heat exchanger of claim 5 wherein one or both of the ram and the base are removable from and not fixed to the core.
 12. The heat exchanger of claim 8 wherein a plurality of intermediate members are provided and the drive system is coupled to multiple intermediate members to simultaneously drive said multiple intermediate members.
 13. The heat exchanger of claim 12 wherein the drive system includes a chain or belt engaged with said multiple intermediate members and wherein one intermediate member is a driving member directly driven by a drive and the other intermediate members are driven members driven by the driving member through the chain or belt.
 14. The heat exchanger of claim 5 wherein the intermediate members include a biasing member.
 15. The heat exchanger of claim 14 wherein the biasing member facilitates expansion of the core.
 16. The heat exchanger of claim 1 wherein the core control assembly is disposed outboard of the core.
 17. The heat exchanger of claim 1 wherein a portion of the core control assembly extends through the core.
 18. The heat exchanger of claim 1 wherein the core control assembly limits the extent to which the core can be expanded.
 19. A heat exchanger, comprising: a core having a longitudinal axis and an periphery disposed about the longitudinal axis, the core including a plurality of resilient corrugated layers stacked along the longitudinal axis with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery; a core control assembly having a pair of end plates disposed on opposed ends of the core and at least one intermediate member interconnecting the end plates to control movement of the core control assembly between a compressed position where the end plates are spaced apart by a first distance and an uncompressed position where the end plates are spaced apart by a second distance greater than the first distance, such that the core expands to increase a cross-sectional area of the passages at the periphery when the core control assembly is moved to the uncompressed position; and a housing having a shell and at least one cover mounted to the shell to surround the core and the core control assembly.
 20. The heat exchanger of claim 19 wherein the intermediate member includes a first connector that is carried by one of the end plates and has a threaded portion, a second connector carried by the other of the end plates and having a threaded portion, and a third connector that interconnects the first and second connectors.
 21. The heat exchanger of claim 20, wherein the first connector is threaded in a first direction, the second connector is threaded in a second direction opposite the first direction, and the third connector has one end threaded in the first direction to engage the first connector and another end threaded in the second direction to engage the second connector.
 22. The heat exchanger of claim 19, wherein each intermediate member includes a plurality of leg portions in serial connection between the end plates, with each leg portion having a pair of opposed ends threaded in opposite directions with respect to each other, such that rotation of one segment in one direction moves the core control assembly toward its uncompressed position and rotation of the leg in an opposite direction moves the core control assembly toward its compressed position.
 23. The heat exchanger of claim 19, further comprising at least one biasing member carried by at least one of the end plates and the intermediate member to facilitate moving the core control assembly toward the uncompressed position.
 24. A method of accessing a heat exchanger core, comprising: moving an intermediate member in a first direction; moving a core control assembly that is associated with the intermediate member toward an uncompressed position with respect to a base; expanding the core along a longitudinal axis between the ram and the base, with the core having an periphery and a plurality of resilient corrugated layers stacked along the longitudinal axis with a plurality of passages interleaved therebetween, a portion of the passages extending and open to the periphery and having a cross-sectional area at the periphery; and increasing the cross-sectional area of the passages at the periphery.
 25. The method of claim 24, further comprising inserting a cleaner into at least one passage at the periphery of the core to clean the core.
 26. The method of claim 24, wherein the step of inserting a cleaner is accomplished by inserting a tool into a passage, injecting a cleaning solvent into a passage, or injecting a fluid under pressure into a passage. 